The acceleration is amazing for a widely available model that can also carry the whole family.

Elon Musk is giving Tesla Model S P100D owners an early Easter Egg in December by unlocking the ability for the electric sedan to reach 60 miles per hour (97 kilometers per hour) is an absolutely astounding 2.4 seconds and cover the quarter mile in 10.6 seconds. The tweak should also let a Model X P100D accelerate to 60 in 2.8 seconds, which is still ludicrously fast.

Musk made the announcements on Twitter and later clarified the upgrades would apply to all 100D vehicles because the Easter Egg was simply a software optimization.

Electrek points out that Musk is likely referring to Tesla’s 8.1 software update. Among the upgrades is the ability for owners to control maximum and minimum values for the always-on temperature control that lets people keep the cabin within a specific range, even when the vehicle is off. We wonder how long it might take people to discover the Easter Egg that gives their Model S or X a little more zip.

Musk teased the Easter Egg as few weeks ago when he enigmatically promised the tweak “uncorks the full performance.” He definitely wasn’t joking.

This upcoming surprise is on track to be Tesla’s best Easter Egg ever. In the past, the company hid a “Rainbow Road” mode in the Autopilot system and referenced Musk’s submersible Lotus Esprit from The Spy Who Loved Me.